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Bob F

wrote:
On Fri, 11 Dec 2009 20:36:56 -0500, mcp6453 wrote:

Home Depot is hawking a system for recirculating hot water such that
each faucet in the home has instant hot water. Does anyone have any
comments, good or bad, about these?

Complex and innefficient.
Best way to have "instant" hot water is to have a small water heater
at the point of use which supplies hot water immediately on demand,
untill the cold water has come through the pipes. You get HOT water
right away, then the temperature drops a little bit if you use more
than the capacity of the small heater as the cold bollus comes
through, then back to hot.

Except the small heater will inevitably be electric, which cost significantly
more to run than gas. Pumping a little cold water back to the heater costs next
to nothing, and saves water over running the water.

Plus, the extra heater is one more to fail/replace regularly.